Recommended Dosage of Melatonin
Based on current evidence, melatonin is typically administered at doses of 2-5 mg for adults, with 3 mg being a common starting dose, though the American Academy of Sleep Medicine suggests against using melatonin for primary insomnia in adults. 1, 2
Adult Dosing Recommendations
- The American Academy of Sleep Medicine recommends a dose of 5 mg of melatonin taken between 19:00-21:00 for adults with Delayed Sleep-Wake Phase Disorder (DSWPD) 2
- For general sleep disorders in adults, a starting dose of 3 mg immediate-release melatonin is suggested, with dose titration in 3 mg increments if needed 2, 3
- For elderly patients (>55 years), a lower dose of 2 mg prolonged-release melatonin has shown some benefit 2, 4
- The American Academy of Sleep Medicine suggests against using melatonin at 2 mg doses for primary insomnia in adults (weak recommendation) 1
Pediatric Dosing Recommendations
- For children with DSWPD without comorbidities, a weight-based dose of 0.15 mg/kg taken 1.5-2.0 hours before habitual bedtime is recommended 2, 3
- For children with DSWPD and psychiatric comorbidities, fast-release melatonin at 3-5 mg is recommended (3 mg if <40 kg and 5 mg if >40 kg) 2, 3
- Effective doses in children range from 0.5 to 3 mg according to research evidence 5
Dosage Forms and Timing
- Immediate-release formulations appear more effective than slow-release formulations for sleep onset 2
- Melatonin should be taken close to the target bedtime (typically 10pm to midnight) for optimal effectiveness 6
- Commercial preparations commonly available include 3 mg tablets 7
Safety Profile and Side Effects
- Melatonin is generally considered safe with few serious adverse effects reported 1, 8
- Most common side effects include daytime sleepiness (1.66%), headache (0.74%), and other sleep-related effects (0.74%) 3
- Higher doses (≥10 mg) appear to have a good safety profile but may increase minor adverse events such as drowsiness, headache, and dizziness 8
- Caution is advised when prescribing to patients taking warfarin and to patients with epilepsy due to potential interactions 1, 2, 3
Dosage Considerations for Specific Conditions
- For jet lag prevention, doses between 0.5 and 5 mg are similarly effective, with 5 mg providing faster sleep onset and better sleep quality than 0.5 mg 6
- For elderly patients with insomnia, doses ranging from 0.5 mg to 6 mg have been studied, with significant decreases in sleep latency observed 9
- A recent study showed that 5 mg melatonin significantly increased sleep efficiency in older adults during both biological day and night 4
Important Clinical Considerations
- Choose reputable formulations (United States Pharmacopeial Convention Verified) for more reliable dosing 1
- Lower doses may be more effective than higher doses due to potential receptor desensitization 2
- Morning grogginess and "hangover" effects are more commonly reported with higher doses 2
- For adults with DSWPD, a treatment duration of 28 days has shown efficacy 2
Pitfalls and Caveats
- Timing of melatonin dose is critical - if taken too early in the day, it may cause sleepiness and delay adaptation to local time 6
- The American Academy of Sleep Medicine suggests against using melatonin for primary insomnia in adults, indicating limited efficacy for this specific condition 1
- Quality control of melatonin products varies widely, affecting the reliability of stated doses 1
- Evidence for long-term safety is limited, as many studies are of short duration 2